Reagent is an interface between ClojureScript and react. It allows you to define efficient React components using nothing but plain ClojureScript functions and data, that describe your UI using a Hiccup-like syntax.
Example:-
(defn sample-component []
[:div
[:p "I am a component!"]
[:p.someclass
"I have " [:strong "bold"] "text."]])
Output:
I am a component!
I have bold text.